This schedules your sitemap to be crawled by our systems. Once you use the
Search Console for your site, you get the added benefit of automatic crawl
errors notifications. Later, you can use the reports to analyze and fix issues
with your URLs or content.

Notify us of changes

When you make changes to your structured data and you want to notify our
systems ahead of our regular schedule, you can resubmit your sitemap to Search
Console following the same process you used to submit your first sitemap.

If you use XML format, change the <lastmod> field to the date of the change.
Read more about this field in the Sitemap.org tag definitions.
Other XML files have a similar field, such as <updated> for Atom XML.
You can also learn how to compute this date.

If you prefer, we also support the following programmatic methods to notify us
of your content updates:

Ping Google specifically with the location of the sitemap:
(http://www.google.com/ping?sitemap=URL/of/file)

Use Pubsubhubbub
if you use Atom/RSS for your sitemap and want to broadcast your changes to other search
engines in addition to Google.